TY - JOUR T1 - Principles and Practice of Infectious Diseases JF - Journal of Clinical Pathology JO - J Clin Pathol SP - 523 LP - 523 DO - 10.1136/jcp.43.6.523-e VL - 43 IS - 6 AU - GL Ridgway Y1 - 1990/06/01 UR - http://jcp.bmj.com/content/43/6/523.5.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -